The Washington University NIGMS Biomedical Resource proposes to continue its 37 years of support for biomedical research through the development of technology based on mass spectrometry (MS). The Resource will pursue this in three areas: 1) The characterization of complex lipids and lipid biosynthesis with a focus on a) pathogenic microorganisms like trypanosomes and mycobacteria and the biosynthetic pathways that offer targets for therapy, b) the characterization of lipid antigens, and c) lipid mediators o fatty acid synthase; 2) The establishment of a biophysics center that offers MS-based tools to probe protein dynamics, protein interactions, protein complex stoichiometry and structure, and membrane proteins using a) hydrogen deuterium exchange MS, b) fast photochemical oxidation of proteins, c) top-down analysis of proteins, and d) crosslinking methods for complexes; and 3) the extension of high energy collisional activation methods for the study of complex lipids and large peptides, especially those predicted from genomic data. This technology development will be driven by nearly three dozen collaborative efforts that are broad in scientific and geographic scope and focused on the study of human health and disease. The technology will be made available to other collaborators through our extensive dissemination and training efforts.